The manufacture of optical gratings is an important technology in the three-dimensional display and the dual-field-of-view display. The optical grating is composed of a group of light-shielding stripes and light-transmitting stripes among the light-shielding stripes.
In the related art, the optical grating may be formed through photo-etching black photoresist, and one process of forming the optical grating includes: coating black photoresist on a transparent substrate; baking the black photoresist at a high temperature and then curing the black photoresist; exposing the photoresist with a mask plate; and arranging the substrate with the exposed photoresist into a developing solution to develop them, and then the exposed photoresist is reserved and the photoresist which are not exposed is removed, so as to form the light-shielding stripes and light-transmitting stripes among the light-shielding stripes.
In a liquid crystal display device, the optical grating is formed on an outer surface of a liquid crystal display panel so as to make the device light and thin. The liquid crystal display panel includes a color filter substrate and an array substrate that are oppositely arranged to form a cell, and the optical grating may be manufactured on the color filter substrate or the array substrate. Taking an example that the optical grating is manufactured on the color filter substrate, when the optical grating is first manufactured on a base substrate and then the base substrate is inverted to perform a subsequent color filter manufacture and a cell process, a chamber where the subsequent process is performed may be polluted due to black pigments contained in the optical grating. Further, in order to ensure that transmittance of the light shielding areas of the optical grating is low enough, thicknesses of the black stripes is generally in a range of 1 micron to 3 microns, and this may result in that the base substrate may not be absorbed firmly in a subsequent vacuum adsorption process. When the color filter manufacturing and the cell process are completed first and then the optical grating is manufactured on an outer surface of the color filter substrate, the liquid crystal cell may be corroded after being baked at a high temperature and steeped in the developing solution, and the liquid crystals may be denatured under ultraviolet light.